Temporary accumulation management device

ABSTRACT

This invention manages temporary storage of content data according to guidelines.  
     According to this invention, when temporary storage of a recording transport stream TS 3  which is allowed to be temporarily stored in a recording medium so as to be reproducible only within a temporary storage allowable time is managed, a reproducible start point indicating a start point from which the recording transport stream TS 3  can be reproduced is associated with a first time stamp out of the time stamps of the GOPs of the recording transport stream TS 3 , and every time when a period from a time stamp associated with the reproducible start point to the current time reaches a temporary storage allowable time, the reproducible start point is re-associated to another time stamp following the time stamp, so that an overtime part of the recording transport stream TS 3  can be removed from a reproducible range so as to easily and correctly disable its reproduction, thus being capable of easily and correctly managing the temporary storage of the recording transport stream TS 3.

TECHNICAL FIELD

This invention relates to a temporary storage management apparatus, andis suitably applied to a recording/reproducing apparatus forrecording/reproducing the video/audio data of a digital televisionprogram comprising content data for digital terrestrial televisionbroadcasting, for example.

BACKGROUND ART

Now, as to digital terrestrial television broadcasting, operationalguidelines for starting broadcasting have been drafted, and broadcastingof three kinds of digital television programs has been proposed, i.e.,digital television programs (hereinafter, referred to as copy protectedprograms) inhibiting copy (hereinafter, referred to as copy) for storagebecause of copyright protection, digital television programs inhibitingre-copy (that is, allowing only copy one generation), and digital,television programs allowing copy without restrictions.

In addition, according to the operational guidelines for digitalterrestrial television broadcasting, with recording media such as thehard disk drives of recording/reproducing apparatuses, even copyprotected programs are allowed to be temporarily stored so as to bereproduced (that is, temporary recording of the video/audio data of copyprotected programs) from a time (hereinafter, referred to as a temporarystorage start time) of receiving their video/audio data at broadcastingtime or of performing a process for watching on the video/audio data atthe broadcasting time, for a prescribed temporary storage allowable time(for example, 90 minutes), and also only the copy protected programstemporarily stored within the temporary storage allowable time areallowed to be watched.

In actual, according to the operational guidelines for digitalterrestrial television broadcasting, to temporarily store a copyprotected program, the video/audio data of the copy protected program ismanaged on a management time (for example, one minute) basis, themanagement time shorter than the temporary storage allowable time. Forexample, if a part is stored at 1:00, its reproduction is disabledwithin a prescribed reproduction disabling time (for example, oneminute) after a lapse of the temporary storage allowable time (2:30).Similarly, if a part is stored at 1:01, its reproduction is disabledwithin the reproduction disabling time after a lapse of the temporarystorage allowable time (2:31). In this way, copy protected programs arerestricted so that the reproduction of parts (hereinafter, referred toas overtime parts) stored over the temporary storage allowable time issequentially disabled (for example, refer to non patent reference 1)

Non patent reference 1 “Operational guidelines for digital terrestrialtelevision broadcasting, Technical report, ARIB TR-B14, 1.2 edition(third part)”, Association of Radio Industries and Businessescorporation, Established on Jan. 24, 2002, 1.1 revision on Jul. 25,2002, 1.2 revision on Nov. 27, 2002, P8.3, 8.19.

By the way, the operational guidelines for digital terrestrialtelevision broadcasting exemplifies, for example, a method (hereinafter,referred to as data deletion method) of sequentially deleting overtimeparts of the video/audio data D1 of a copy protected program TP1 withina reproduction disabling time, as shown in FIG. 8, as a method ofdisabling the reproduction of overtime parts of copy protected programs.

In addition, the operational guidelines for digital terrestrialtelevision broadcasting prescribes that a recording/reproducingapparatus encrypts (hereinafter, referred to as locally encrypts) andrecords the video/audio data D1 of a copy protected program TP1 whentemporarily storing the copy protected program TP1. As shown in FIG. 9,the operational guidelines also exemplify a method (hereinafter,referred to as a local scramble key deletion method) of locallyencrypting the video/audio data D1 of the copy protected program TP1with encryption key data (hereinafter, referred to as local scramble keydata) K which is different for every part TG1 of a management time unitand disabling decoding of the video/audio data D1 corresponding toovertime parts D1A by sequentially deleting the local scramble key dataused for the local encryption of the overtime parts D1A (that is, amethod of disabling reproduction).

However, the data deletion method has a problem in that, since therecording/reproducing apparatus records and manages the video/audio dataD1 of the copy protected program TP1 as a file, a special file systemfor sequentially deleting only the overtime parts should be created forthe video/audio data D1 of the copy protected program TP1 temporarilystored and therefore the temporary storage of the copy protected programcannot be managed easily according to the guidelines.

In addition, according to the local scramble key deletion method, therecording/reproducing apparatus is required to sequentially create thelocal scramble key data K to be used for the local encryption every timewhen temporarily storing a part TG of the management time unit of thevideo/audio data D1, and also is required to manage a large number (forexample, 90) of local scramble keys K for the temporary storageallowable time, resulting in complicating a process to temporarily storethe copy protected program TP1. As a result, even the local scramble keydeletion method is insufficient to manage the temporary storage of copyprotected programs according to the guidelines.

DISCLOSURE OF THE INVENTION

The invention has been made in view of foregoing and proposes atemporary storage management apparatus capable of easily and correctlymanaging the temporary storage of content data according to theguidelines.

To solve the above problems, in this invention, in order to manage thetemporary storage of content data which is allowed to be temporarilystored for reproduction only for a prescribed temporary storageallowable time in a recording medium, a reproducible start pointrepresenting a start point from which the content data can be reproducedis associated with the first temporary storage start time out of thetemporary storage start times each for every prescribed part of thecontent data, and every time when a period from the temporary storagestart time associated with the reproducible start point until thecurrent time reaches the temporary storage allowable time, anothertemporary storage start time after the temporary storage start time isre-associated with the reproducible start point.

Therefore, overtime parts of the content data temporarily stored areremoved from the reproducible range which is a range temporarily storedwithin the temporary storage allowable time, by being sequentiallylocated temporally before the reproducible start point.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing one embodiment of the entireconstruction of a recording/reproducing apparatus according to thisinvention.

FIG. 2 is a schematic diagram showing a change history of copyrightprotection information.

FIG. 3 is a schematic diagram explaining the recording of a copypermitted program.

FIG. 4 is a schematic diagram explaining the update of reproducible endpoint information for recording a copy permitted program.

FIG. 5 is a schematic diagram explaining the temporary storage of a copyprotected program.

FIG. 6 is a schematic diagram explaining the update of reproduciblestart point information and reproducible end point information for thetemporary storage of a copy protected program.

FIG. 7 is a flowchart showing a temporary storage management procedure.

FIG. 8 is a schematic diagram explaining the disabling of reproductionof a copy protected program with a data deletion method.

FIG. 9 is a schematic diagram explaining the disabling of reproductionof a copy protected program with a local scramble key deletion method.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, one embodiment of this invention will be described indetail with reference to the accompanying drawings.

Referring to FIG. 1, reference numeral 1 shows a recording/reproducingapparatus to which this invention is implemented. Connected to a CPU(Central Processing Unit) 2 is a plurality of circuit blocks including avolatile memory 4 serving as a work area of the CPU 2. The CPU 20controls each circuit block according to various programs including arecording processing program, a reproduction processing program and atemporary storage management program being stored in the hard disk of ahard disk drive 5, so as to execute processes for watching and forrecording/reproduction on digital television programs of digitalterrestrial television broadcasting, analog television programs ofanalog terrestrial television broadcasting, and video/audio(hereinafter, referred to as external video/audio) supplied fromexternal devices such as video cameras.

When an analog television program of the analog terrestrial televisionbroadcasting is watched, the CPU 2 first controls an analog tuner 10according to the channel of the analog television broadcasting specifiedfor watching the desired analog television program via an operating unit9 such as a remote controller.

The analog tuner 10 takes in a television signal group S1 for aplurality of channels of the analog terrestrial television broadcastingreceived by an antenna (not shown), selects the television signal of thechannel specified for watching, out of the taken television signal groupS1 and applies a wave detection process and a demodulation process, andsends the obtained analog video signal S2 and audio signal S3 to asignal processing circuit 11.

Out of the video signal S2 and the audio signal S3 given from the analogtuner 10, the signal processing circuit 11 performs analog-to-digitalconversion on the video signal S2 and sends the obtained video data D10to an MPEG encoder 12, and performs the analog-to-digital conversion onthe audio signal S3 and sends the obtained audio data D11 to the MPEGencoder 12.

The MPEG encoder 12 compresses and encodes the video data D10 and theaudio data D11 given from the signal processing circuit 11 with the MPEG(Moving Picture Experts Group) 2 standards, and converts the resultantcompressed and encoded video data and compressed and encoded audio datain an ES (Elementary Stream) format into TS (Transport Stream) packetsfor every prescribed unit, thereby creating video TS packet data andaudio TS packet data.

Then the MPEG encoder 12 performs time division multiplexing on thevideo TS packet data and the audio TS packet data, and sends theobtained transport stream TS1 to a demultiplexer 15.

The demultiplexer 15 divides the transport stream TS1 given from theMPEG encoder 12, into video TS packet data and audio TS packet data.

In addition, the demultiplexer 15 creates compressed and encoded videodata D12 in the ES format based on the video TS packet data and sendsthis to the video decoder 16, and creates compressed and encoded audiodata D13 in the ES format based on the audio TS packet data and sendsthis to the audio decoder 17.

Then the video decoder 16 creates video data by decoding the compressedand encoded video data D12 given from the demultiplexer 15 with theMPEG2 standards, and performs the digital-to-analog conversion on thecreated video data and sends the obtained video signal S2 to an externalvideo display unit 20.

The audio decoder 17 creates audio data by decoding the compressed andencoded audio data D13 given from the demultiplexer 15 with the MPEG2standards, and performs the digital-to-analog conversion on the createdaudio data and sends the obtained audio signal S3 to an external audiooutput unit 21.

Thereby, the recording/reproducing apparatus 1 is capable of displayingthe program video of the analog television program based on the videosignal S2 on the video display unit 20 and simultaneously, outputtingthe program sound of the analog television program based on the audiosignal S3 from the audio output unit 21, so that a user can watch thedesired analog television program.

On the other hand, when an external input is selected via the operatingunit 9 to watch external video/audio, the CPU 2 controls the analogtuner 10 and the digital tuner 22 to stop their operation accordingly.

In this situation, the signal processing circuit 11 takes in an analogvideo signal S5 and audio video signal S6 supplied from an externaldevice, via an external input interface 23.

Then the signal processing circuit 11, the MPEG encoder 12, thedemultiplexer 15, the video decoder 16, and the audio decoder 17 executethe same processes as the above-described case of watching an analogtelevision program.

Thereby, the recording/reproducing apparatus 1 is capable of displayingthe video based on the video signal S5 on the video display unit 20 andoutputting the sound based on the audio signal S6 from the audio outputunit 21, so that the user can watch the external video/audio.

On the other hand, to record an analog television program, the CPU 2controls the analog tuner 10 according to the channel for recordingspecified via the operating unit 9.

At this time, the analog tuner 10 takes in a television signal group S1for a plurality of channels of the analog terrestrial televisionbroadcasting received by the antenna, selects the television signal ofthe channel specified for recording, out of the taken television signalgroup S1 and applies the wave detection process and the demodulationprocess, and sends the obtained analog video signal S2 and audio signalS3 to the signal processing circuit 11.

The signal processing circuit 11 creates the video data D10 and theaudio data D11 based on the video signal S2 and the audio signal S3 andsends these to the MPEG encoder 12, as in the above-described case ofwatching an analog television program.

The MPEG encoder 12 creates a transport stream TS1 based on the videodata D10 and the audio data D11 and sends these to the demultipexer 15,as in the above-described case of watching an analog television program.

The demultiplexer 15 sends the transport stream TS1 given from the MPEGencoder 12, to the hard disk drive 5 via a scrambler 24 and a memory 25as it is, so as to record the transport stream TS1 in the hard disk as afile.

In this way, the recording/reproducing apparatus 1 records the transportstream TS1 corresponding to the analog television program of thespecified channel in the hard disk after recording start is instructedvia the operating unit 9 or the like until recording end is instructed,thus being capable of recording the desired analog television program.

On the other hand, to reproduce an analog television program, the CPU 2controls the hard disk drive 5 via the memory 25 based on the analogtelevision program specified for reproduction via the operating unit 9and in response to a reproduction command for the analog televisionprogram.

Thereby the hard disk drive 5 reads the transport stream TS1 of thespecified analog television program from the hard disk, and sends theread transport stream TS1 to the demultiplexer 15 via the memory 25 andthe descrambler 26 in order.

At this time, the demultiplexer 15 applies the same processes as theabove-described case of watching an analog television program, on thetransport stream TS1 reproduced from the hard disk, and sends theobtained compressed and encoded video data D12 to the video decoder 16and sends the compressed and encoded audio data D13 to the audio decoder17.

The video decoder 16 and the audio decoder 17 perform the same processesas the above-described case of watching an analog television program,and sends the video signal S2 based on the compressed and encoded videodata D12 to the external video display unit 20 and sends the audiosignal S3 based on the compressed and encoded audio data D13 to theexternal audio output unit 21.

Thereby, the recording/reproducing apparatus 1 is capable of displayingthe program video of the analog television program based on the videosignal S2 on the video display unit 20 and outputting the program soundof the analog television program based on the audio signal S3 from theaudio output unit 21, so that the user can watch the desired analogtelevision program once recorded.

On the other hand, when an external input is selected and recording isinstructed via the operating unit 9 to record external video/audio, theCPU 2 controls the analog tuner 10 and the digital tuner 22 to stoptheir operation accordingly.

In this situation, the signal processing circuit 11 takes in the analogvideo signal S5 and audio signal S6 supplied from the external device,via the external input interface 23.

Then the signal processing circuit 11, the MPEG encoder 12, thedemultiplexer 15, the scrambler 24, the memory 25, and the hard diskdrive 5 perform the same processes as the above-described case ofrecording an analog television program.

Thereby, the recording/reproducing apparatus 1 creates a transportstream comprising compressed and encoded video data and compressed andencoded audio data corresponding to the external video/audio and recordsthese in the hard disk of the hard disk drive 5 as a file, afterrecording start is instructed via the operating unit 9 or the like untilrecording end is instructed.

On the other hand, to reproduce external video/audio, the CPU 2 controlsthe hard disk drive 5 via the memory 25 based on the externalvideo/audio for reproduction specified via the operating unit 9 and inresponse to a reproduction command for the external video/audio.

Thereby the hard disk drive 5 reads the transport stream of thespecified external video/audio from the hard disk, and sends the readtransport stream to the demultiplexer 15 via the memory 25 and thedescrambler 26 in order.

Then the demultiplexer 15, the video decoder 16, the audio decoder 17perform the same processes as the above-described case of reproducing ananalog television program.

Thereby the recording/reproducing apparatus 1 is capable of displayingthe video of the external video/audio based on the video signal S5 onthe video display unit 20 and outputting the sound of the externalvideo/audio based on the audio signal S6 from the audio output unit 21,so that the user can watch the external video/audio once recorded.

By the way, from a broadcasting station (not shown) for the digitalterrestrial television broadcasting, a plurality of transport streams issent as television signals S10, the transport signals obtained bycompressing and encoding digital video data and audio data of digitalterrestrial television programs with the MPEG2 standards, sequentiallyconverting the resultant into PES (Packetized Elementary Stream) packetsand TS packets, and performing the time division multiplexing on theobtained video TS packet data and audio TS packet data for everyprescribed channels together with section TS packet data, the section TSpacket data obtained by converting section data into TS packets, thesection data storing additional information to specify the digitaltelevision programs.

To watch a digital television program, the CPU 2 controls the digitaltuner 22 according to a channel (hereinafter, referred to watchingspecified channel) for watching specified via the operating unit 9, inthe digital television broadcasting.

The digital tuner 22 takes in a plurality of television signals S10 ofthe digital terrestrial television broadcasting received by the antenna(not shown), selects the television signal S10 of the watching specifiedchannel out of the taken television signals S10, performs the wavedetection process and the demodulation process, and sends the obtaineddigital transport stream TS2 to the descrambler 30.

In this connection, to let only users who are allowed to watch thedigital television program of the channel corresponding to the transportstream TS2, the transport stream TS2 is previously encrypted on thebroadcasting station side.

Therefore, in a case where the transport stream TS2 of the watchingspecified channel is previously encrypted on the broadcasting stationside, the CPU 2 reads scramble key data D15 from an IC (IntegratedCircuit) card 31 via the card interface 32 and sends this to thedescrambler 30, the IC card provided from the provider of the digitalterrestrial television broadcasting to the user.

In a case where the transport stream TS2 given from the digital tuner 22is encrypted, the descrambler 30 decodes the transport stream TS2 withthe scramble key data D15 given from the CPU 2, and sends the resultantto the demultiplexer 15.

In a case where the transport stream TS2 given from the digital tuner 22is not encrypted, the descrambler 30 sends the transport stream TS2 tothe demultiplexer 15 as it is.

The demultiplexer 15 is given a PID (Packet IDentifier) to specifysection TS packet data, from the CPU 2, and separates the section TSpacket data from the transport stream TS2 given from the descrambler 30,based on the PID, and separates the video TS packet data and the audioTS packet data of the digital television program based on the PID whichis stored in the section TS packet data and specifies the digitaltelevision program of the watching specified channel.

In addition, the demultiplexer 15 creates the video PES packet data D16based on the video TS packet data and creates the audio PES packet dataD17 based on the audio TS packet data, and sends the created video PESpacket data D16 to the video decoder 16 and sends the audio PES packetdata D17 to the audio decoder 17.

Further, the demultiplexer 15 creates the original section data D18based on the section TS packet data and sends this to the memory 18.

Then the CPU 2 reads the section data D18 from the memory 18, andcontrols the video decoder 16 and the audio decoder 17 in an order ofdecoding indicated by the additional information being stored in theread section data D18.

The video decoder 16 creates the original video data by decoding thevideo PES packet data D16 given from the demultiplexer 15, with theMPEG2 standards, performs the digital-to-analog conversion on thecreated video data, and sends the obtained video signal S11 to theexternal video display unit 20.

In addition, the audio decoder 17 creates the original audio data bydecoding the audio PES packet data D17 given from the demultiplexer 15with the MPEG2 standards, performs the digital-to-analog conversion onthe created audio data and sends the obtained audio signal S12 to theexternal audio output unit 21.

Thereby, the recording/reproducing apparatus 1 is capable of displayingthe program video of the digital television program based on the videosignal S11 on the video display unit 20 and outputting the program soundof the digital television program based on the audio signal S12 from theaudio output unit 21, so that the user can watch the desired digitaltelevision program.

In addition to the above configuration, in a case of thisrecording/reproducing apparatus 1, when a recording command for adigital television program being watched is entered via, for example,the operating unit 9 while the digital television program of a desiredchannel is being watched, the CPU 2 controls the digital tuner 22, thedescrambler 30, the video decoder 16, the audio decoder 17, and thememory 18 so as to perform the same processes as the above-describedcase of watching a digital television program, and also controls thedemultiplexer 15 in response to the recording command.

In this case, the demultiplexer 15 separates section TS packet data, andthe video TS packet data and audio TS packet data of the digitaltelevision program being watched and to be recorded, from the transportstream TS2 given from the descrambler 30, as in the above-described caseof watching a digital television program.

In addition, the demultiplexer 15 sends the video PES packet data D16created based on the video TS packet data, the audio PES packet data D17created based on the audio TS packet data, and the section data D18created based on the section TS packet data, to the video decoder 16,the audio decoder 17, and the memory 18, so as to allow the desireddigital television program to be watched at broadcasting time.

In addition, the demultiplexer 15 creates the recording transport streamTS3 corresponding to the digital television program to be recorded, byperforming the time division multiplexing on the section TS packet data,the video TS packet data and the audio TS packet data separated from thetransport stream TS2, and sends this to the information extractioncircuit 33 and the scrambler 24.

Then the CPU 2 reads the section data D18 from the memory 18 andextracts program information to specify the digital television programto be recorded, from the read section data D18, recognizes, for example,switching of the digital television program to be recorded (that is,broadcasting end and broadcasting start), creates local scramble keydata D20 which is different depending on television programs to berecorded based on the recognition result, and sends the created localscramble key data D20 to the scrambler 24.

Therefore, the scrambler 24 locally encrypts the compressed and encodedvideo data and the compressed and encoded audio data being stored in therecording transport stream TS3 given from the demultiplexer 15, with thelocal scramble key data D20 and sends the obtained encrypted transportstream TS4 to the memory 25, and encrypts the local scramble key dataD20 with information (manufacturing number of the recording/reproducingapparatus 1 or the like) unique to the recording/reproducing apparatus 1and sends the obtained encrypted scramble key data D21 to the memory 25.

Therefore, the CPU 2 controls the memory 25 to store the encryptedtransport stream TS4 corresponding to the digital television programbeing watched, in the hard disk of the hard disk drive 5 as a streamfile.

On the other hand, the information extraction circuit 33 extracts streammanagement information which is used for reproducing a recorded digitaltelevision program (that is, used for reproducing the recordingtransport stream TS3), and program information from the section TSpacket data included in the recording transport stream TS3 given fromthe demultiplexer 15.

In a case where the beginning part of GOP (Group Of Picture) accompaniedwith a sequence header which is randomly accessible is stored in thedata storage part following a PES header of the video TS packet dataincluded in the recording transport stream TS3, the PES header storesmanagement information (hereinafter, referred to as time stamp, simply)for time for reproduction output (that is, this time is a time when thewatching process was performed and is a temporary storage start time)represented by a time with about a 26-hour cycle called PTS(Presentation Time Stamp) added to a frame image which is the beginningof the GOP and is assigned with an inter frame encoded image (that is, I(Intra) picture).

Then since GOPs are sequentially created for the data of frame images(that is, about 15 frame images) which continue for a prescribed time(for example, about 0.5 seconds) shorter than the temporary storagemanagement time unit, from the beginning of the video data out of aplurality of continuous frame images composing the video data of thedigital television program, the time stamp represents time which variesat a reproduction period (for example, about 0.5 seconds) of a frameimage which is the beginning of the GOP and is assigned with the interframe encoded image.

Therefore, to randomly access the recording transport stream TS3 at atime of reproduction, the information extraction circuit 33 sequentiallyextracts the time stamps from a plurality of PES packets of the video TSpacket data included in the recording transport stream TS3 as thebroadcasting time passes, and sends the extracted time stamps to the CPU2 via the memory 25.

Further, the section data D18 stores copyright protection informationfor the digital television program to be recorded, and the copyrightprotection information indicating one restriction set to a digitaltelevision program by a broadcasting station, out of three selections,copy never, copy one generation (that is, re-copy is inhibited) and copyfree without restrictions.

Therefore, as shown in FIG. 2, the CPU 2 extracts the copyrightprotection information from the section data D18 read from the memory 18and every time when the contents of the copyright protection informationare changed according to switching between digital television programsto be recorded, stores the change time (that is, this time is thebroadcasting start time of a new digital television program and isreferred to as change time) in the volatile memory 4 together with thecontents of the changed copyright protection information, therebycreating a change history (hereinafter, referred to as historyinformation) of copyright protection information of digital televisionprograms to be recorded, on the volatile memory 4.

Then, as shown in FIG. 3, when it is determined based on the changehistory of the copyright protection information that the digitaltelevision program being currently recorded is a digital televisionprogram allowing copy one generation or a digital television programallowing copy without restrictions (these are collectively referred toas copy permitted program), the CPU 2 creates, on the memory 25,reproduction procedure information storing a file name (hereinafter,referred to as stream file name) of the encrypted transport stream TS4recorded in the hard disk as a file (that is, as a stream file F1), datamanagement information and program information extracted by theinformation extraction circuit 33 and the encrypted scramble key dataD21, and records the created reproduction procedure information in thehard disk of the hard disk drive 5 as a reproduction procedureinformation file F2.

In addition, on the volatile memory 4, as shown in FIG. 4, the CPU 2creates reproducible start point information indicating a time stampassociated with a reproducible start point by associating the first timestamp with a reproducible start point, the first time stamp firstextracted by the information extraction circuit 33 from the PES headerof the recording start part of the video TS packet data included in therecording transport stream TS3, the reproducible start point indicatingthe start point from which the recording transport stream TS3 can bereproduced.

In addition, when the information extraction circuit 33 extracts thetime stamp from the PES header of the video TS packet data included inthe recording transport stream TS3 next while the copy permitted programis recorded, the CPU 2 creates, on the volatile memory 4, reproducibleend point information indicating a time stamp associated with areproducible end point by associating the extracted time stamp with thereproducible end point indicating an end point until which the recordingtransport stream TS3 can be reproduced.

Then every time when the information extraction circuit 33 extracts atime stamp from a PS header of the video TS packet data, the CPU 2updates, on the volatile memory 4, the contents of the reproducible endpoint information by re-associating another time stamp (in actual, timestamp next to the time stamp associated with the reproducible end point)temporally following the time stamp associated with the reproducible endpoint. Then, finally, the reproducible end point information is updatedby re-associating the time stamp finally extracted from the PES headerof the recording end part of the video TS packet data with thereproducible end point.

In addition, when recording of the encrypted transport stream TS4 in thehard disk starts, the CPU 2 calculates a reproduction disablingdetection time, which is the temporary storage allowable time before thecurrent time, by subtracting the temporary storage allowable time fromthe current time, at prescribed periods within the temporary storagemanagement time.

In addition, by comparing the reproduction disabling detection time withthe change time in the history information, the CPU 2 determines whethera copy protected digital television program (hereinafter, referred to ascopy protected program) was temporarily stored at the reproductiondisabling detection time.

If a copy protected program was not temporarily stored or a copypermitted program was recorded at the reproduction disabling detectiontime, the CPU 2 does not change the correspondence between the timestamp and the reproducible start point, for the copy permitted programrecorded at the reproduction disabling detection time.

When the recording of the encrypted transport stream TS4 correspondingto the copy permitted program in the hard disk is completed, the CPU 2(FIG. 3) creates, on the volatile memory 4, reproduction managementinformation storing reproducible start point information, reproducibleend point information finally obtained by updating the contents, and afile name (hereinafter, referred to as reproduction procedureinformation file name) of the reproduction procedure information fileF2, and sends this to the hard disk drive 5 via the memory 25 as a file,thereby recording the reproduction management information in the harddisk as a reproduction management information file F3.

As described above, the CPU 2 records the stream file F1, thereproduction procedure information file F2, and the reproductionmanagement information file F3, which are sequentially associated witheach other by using the file name, in the hard disk of the hard diskdrive 5, so as to record the copy permitted program in a state where theprogram can be reproduced freely within a reproducible range (in thiscase, entire copy permitted program) from the reproducible start pointto the reproducible end point.

On the other hand, when it is detected based on the history informationbeing stored in the volatile memory 4 that the digital televisionprogram being recorded is a copy protected program, the CPU 2 createsreproduction procedure information in the same manner as theabove-described case, on the memory 25, and reads the createdreproduction procedure information and stores it in the volatile memory4 as a reproduction procedure information file F2, as shown in FIG. 5.

In addition, as shown in FIG. 6, the CPU 2 creates, on the volatilememory 4, reproducible start point information by associating the firsttime stamp first extracted from a PES header of the recording start partof the video TS packet data included in the recording transport streamTS3 with a reproducible start point for reproducing the recordingtransport stream TS3.

Further, when the information extraction circuit 33 extracts a timestamp from a PES header of the video TS packet data included in therecording transport stream TS3 next while the copy protected program isrecorded, the CPU 2 creates, on the volatile memory 4, reproducible endpoint information by associating the extracted time stamp with thereproducible end point for reproducing the recording transport streamTS3.

Then, every time when the information extraction circuit 33 extracts atime stamp from a PES header of the video TS packet data included in therecording transport stream TS3 while the copy protected program isrecorded, the CPU 2 updates, on the volatile memory 4, the contents ofthe reproducible end point information by re-associating another timestamp temporally following the time stamp being associated with thereproducible end point, with the reproducible end point. Then, finally,the reproducible end point information is updated by re-associating thetime stamp finally extracted from the PES header of the recording endpart of the video TS packet data with the reproducible end point.

In addition, similarly to the above-described case of recording a copypermitted program, when the recording of the encrypted transport streamTS4 in the hard disk starts, the CPU 2 calculates a reproductiondisabling detection time by subtracting the temporary storage allowabletime from the current time at a prescribed period within the temporarystorage management time, and compares the calculated reproductiondisabling detection time with the change time in the history informationto determine whether the copy protected program was temporarily storedat the reproduction disabling detection time.

When the copy protected program is being recorded for temporary storageafter the copy permitted program and therefore the copy permittedprogram was recorded at the reproduction disabling detection time, theCPU 2 does not change the time stamp associated with the reproduciblestart point for the copy protected program being recorded because thetemporary storage allowable time is not elapsed after the temporarystorage recording starts.

Further, when the copy protected program being recorded for temporarystorage was recorded at the reproduction disabling detection time andthe reproduction disabling detection time is almost the same as thetemporary storage start time indicated by the time stamp associated withthe reproducible start point, the CPU 2 re-associates another time stamp(in actual, time stamp next to the time stamp associated with thereproducible start point) temporally following the time stamp associatedwith the reproducible start point, with the reproducible start point forthe copy protected program being recorded, and updates the contents ofthe reproducible start point information accordingly.

Therefore, for the recording transport stream TS3 corresponding to thecopy protected program being recorded, the CPU 2 can specify a rangefrom the temporary storage start time indicated by one time stampre-associated with the reproducible start point till the temporarystorage start time indicated by the other time stamp associated with thereproducible end point, as a reproducible range temporary stored fromthe temporary storage start time within the temporary storage allowabletime, and disables the reproduction of a range before the temporarystorage start time indicated by the time stamp re-associated with thereproducible start point, as an unreproducible range stored over thetemporary storage allowable time after the temporary storage start time.

Then when the recording of the encrypted transport stream TS4corresponding to the copy protected program in the hard disk of the harddisk drive 5 is completed, the CPU 2 creates reproduction managementinformation storing reproducible start point information finallyobtained by updating the contents, reproducible end point informationfinally obtained similarly by updating the contents, and a reproductionprocedure information file name, and stores the created reproductionmanagement information in the volatile memory 4 as a reproductionmanagement information file F3.

As described above, the CPU 2 records the stream file F1 in the harddisk of the hard disk drive 5 and stores the reproduction procedureinformation file F2 and the reproduction management information file F3sequentially associated with the stream file F1 in the volatile memory4, and thus the copy protected program can be temporarily stored in astate where the program can be reproduced freely within the reproduciblerange between the reproducible start point information and thereproducible end point information.

By the way, while a copy protected program or a copy permitted programis being recorded, when another copy protected program was recorded atthe reproduction disabling detection time and the temporary storagestart time indicated by the time stamp associated with the reproduciblestart point is almost the same as the reproduction disabling detectiontime in the copy protected program, the CPU 2 updates the contents ofthe reproducible start point information in the reproduction managementinformation file F3 by re-associating another time stamp temporallyfollowing the time stamp associated with the reproducible start point,with the reproducible start point within the reproduction disablingtime.

In this connection, since the temporary storage allowable time is notelapsed after the temporary storage recording starts for the copyprotected program being recorded for the temporary storage, the CPU 2does not change the time stamp associated with the reproducible startpoint.

Then while the copy protected program or the copy permitted program isbeing recorded, the time stamp associated with the reproducible startpoint can be changed to another time stamp temporally following the timestamp associated with the reproducible start point for such another copyprotected program but the time stamp associated with the reproducibleend point is re-associated with the reproducible start point, and as aresult, if the temporary storage start time indicated by the time stampmatches the reproduction disabling detection time, which means that thecopy protected program is stored over the temporary storage allowabletime, so that the CPU 2 deletes the reproducible start point informationand the reproducible end point information from the correspondingreproduction management information file F3.

In this way, the CPU 2 deletes the reproducible start point informationand the reproducible end point information when the other copy protectedprogram is temporarily stored over the temporary storage allowable timeafter the temporary storage start time, so that the reproducible rangeof the other copy protected program cannot be specified to disable thereproduction, resulting in preventing the copy protected program frombeing temporarily stored in a state where the program can be reproducedover the temporary storage allowable time.

In addition, even if the recording of the copy protected program iscompleted, the CPU 2 calculates the reproduction disabling detectiontime by subtracting the temporary storage allowable time from thecurrent time at prescribed periods within the temporary storagemanagement time and compares the calculated reproduction disablingdetection time with the change time of the history information, todetermine whether the copy protected program was temporarily stored atthe reproduction disabling detection time.

When, as a result, the copy protected program was recorded for thetemporary storage at the reproduction disabling detection time and thetemporary storage start time indicated by the time stamp associated withthe reproducible start point almost matches the reproduction disablingdetection time in the copy protected program, the CPU 2 changes the timestamp which is associated with the reproducible start time, to atemporally following time stamp in the same manner as above and updatesthe contents of the reproducible start point information in thereproduction management information file F3 accordingly.

Then as a result of repeating the change of the time stamp which isassociated with the reproducible start point, when the temporary storagestart time indicated by the time stamp matches the reproductiondisabling detection time after the time stamp associated with thereproducible end point is re-associated with the reproducible startpoint, the CPU 2 deletes the reproducible start point information andthe reproducible end point information in the corresponding reproductionmanagement information file F3 in the same manner as the above-describedcase, thereby disabling the reproduction with preventing the copyprotected program from being stored in a situation where the program canbe reproduced over the temporary storage allowable time.

As described above, when a copy protected program is temporarily stored,the CPU 2 associates the first time stamp, out of the time stampssequentially extracted from the GOP parts of the recording transportstream TS3 corresponding to the copy protected program, with thereproducible start point, and every time when a period from thetemporary storage start time indicated by the time stamp associated withthe reproducible start point until the current time reaches thetemporary storage allowable time, the CPU 2 re-associates another timestamp temporally following the time stamp with the reproducible startpoint, so as to correctly distinguish between the reproducible range andthe unreproducible range of the recording transport stream TS3 based onthe temporary storage allowable time.

In actual, when the recording/reproducing apparatus 1 starts, the CPU 2executes a temporary storage management process with a temporary storagemanagement program being stored in the hard disk of the hard disk drive5, and enters a temporary storage management procedure RT1 shown in FIG.7 from the start step and moves to step SP1.

At step SP1, the CPU 2 determines whether the recording of a digitaltelevision program starts when watched.

When a negative result is obtained at this step SP1, this means that thedigital television program is desired to be only watched and the userdoes not intend to record it. At this time, the CPU 2 waits for startingrecording at step SP1.

When an affirmative result is obtained at step SP1, on the contrary,this means that since, for example, a customer comes or a telephonerings while the digital television program is watched, the digitaltelevision program is desired to be recorded. In this case, the CPU 2moves to step SP2.

At step SP2, the CPU 2 starts to record the digital television programto be recorded, and thereby locally encrypts and records the recordingtransport stream TS3 corresponding to the television program in the harddisk and creates reproducible start point information by associating atime stamp first extracted from the PES header of he recording startpart of the video TS packet data included in the recording transportstream TS3, with a reproducible start point, and then moves to step SP3.

At step SP3, the CPU 2 determines whether the digital television programis being recorded.

When an affirmative result is obtained at step SP3, this means that acopy protected program or a copy permitted program is being recorded fortemporary storage as the digital television program to be recorded. Atthis time, the CPU 2 moves to step SP4.

At step SP4, the CPU 2 creates reproducible end point information byassociating a time stamp (time stamp temporally following the time stampassociated with the reproducible start point) extracted from a PESheader of the video TS packet data included in the recording transportstream TS3 corresponding to the copy protected program or the copypermitted program being recorded at this time, with the reproducible endpoint, and moves to step SP5.

When a negative result is obtained at step SP3, this means that both acopy protected program and a copy permitted program is not recorded nowbut, for example, a copy protected program recorded for temporarystorage in the past should be prevented from having an overtime part. Atthis time, the CPU 2 moves to step SP5.

At step SP5, the CPU 2 compares a reproduction disabling detection timewhich is the temporary storage allowable time before the current time,with the change time of the history information to detect copyrightprotection information of the digital television program recorded at thereproduction disabling detection time, and moves to step SP6.

At step SP6, the CPU 2 determines whether the contents of the copyrightprotection information of the digital television program recorded at thereproduction disabling time indicates copy never.

When an affirmative result is obtained at step SP6, this means that thecopy protected program was recorded for temporary storage as a digitaltelevision program at the reproduction disabling detection time and thecopy protected program has an overtime part over the temporary storageallowable time after the temporary storage start time indicated by thetime stamp associated with the reproducible start point. At this time,the CPU 2 moves to step SP7.

At step SP7, for the copy protected program recorded at the reproductiondisabling detection time, the CPU 2 re-associates another time stamptemporally following the time stamp associated with the reproduciblestart point, with the reproducible start point and updates the contentsof the reproducible start point information to disable the reproductionof the overtime part, and then moves to step SP8.

When a negative result is obtained at step SP6, this means that a copypermitted program was recorded at the reproduction disabling detectiontime as a digital television program or that the copy protected programis not recorded but a copy protected program is being recorded fortemporary storage, the copy protected program being recorded may have anovertime part. At this time, the CPU 2 moves to step SP8.

At step SP8, the CPU 2 determines whether the reproduction of the copyprotected program temporarily stored was disabled as the temporarystorage allowable time passes.

When a negative result is obtained at step SP8, this means that at leasta part of the copy protected program being recorded for temporarystorage or stored in the past for temporary storage is stored within thetemporary storage allowable time. That is, the reproduction of all thecopy protected program temporarily stored has not been disabled becausethe temporary storage allowable time is not elapsed. At this time, theCPU 2 returns to step SP3.

When an affirmative result is obtained at step SP8, this means that, asa result of sequentially updating the reproducible start pointinformation as the temporary storage allowable time passes for the copyprotected program recorded for temporary storage, the same time stampassociated with the reproducible start point and the reproducible endpoint further matches the reproduction disabling detection time and thereproduction of the copy protected program has been disabled by deletingthe reproducible start point information and the reproducible end pointinformation. At this time, the CPU 2 returns back to step spi.

As described above, while the recording/reproducing apparatus 1 starts,the CPU 2 repeats a process of step SP1 to step SP8 of the temporarystorage management procedure RT1. Even if a copy protected program istemporarily stored when watched, the reproduction of an overtime part isdisabled within the reproduction disabling time, thereby the entire copyprotected program cannot be reproduced over the temporary storageallowable time.

In addition, the CPU 2 records the encrypted transport stream TS4corresponding to a copy protected program temporarily stored, in thehard disk but stores the reproduction procedure information and thereproduction management information required for reproduction of theencrypted transport stream TS4 in the volatile memory 4.

Therefore, even if the recording/reproducing apparatus 1 is stoppedbefore the reproduction of the entire copy protected program temporarilystored is disabled by updating the contents of the reproducible startpoint information, the CPU 2 automatically deletes the reproductionprocedure information and the reproduction management information bystopping supply of power to the volatile memory 4.

Therefore, when the recording/reproducing apparatus 1 starts again, evenif the encrypted transport stream TS4 corresponding to the copyprotected program remains in the hard disk, the CPU 2 can disable itsreproduction, so that the reproduction of the copy protected program canbe disabled so that the program is not stored in a reproducible mannerover the temporary storage allowable time.

Then, at the time of reproducing a copy protected program temporarilystored, the CPU 2 accesses the volatile memory 4 to read the latestreproduction management information corresponding to the copy protectedprogram and also read reproduction procedure information based on thereproduction management information to be reproduced specified with theoperating unit 9.

In this case, the CPU 2 controls the hard disk drive 5 via the memory 25based on the stream file name and stream management information beingstored in the reproduction procedure information and the reproduciblestart point information and reproducible end point information beingstored in the stream reproduction management information.

Thereby, the CPU 2 reads only a data part within the reproducible rangebetween the reproducible start point and the reproducible end pointspecified by the time stamps of the reproducible start point informationand the reproducible end point information from the encrypted transportstream TS4 corresponding to the copy protected program to be reproducedfrom the hard disk, and sends the read data part to the descrambler 26as the reproduction encrypted transport stream TS5.

In addition, the CPU 2 sends the encrypted scramble key data D2 beingstored in the reproduction management information, to the descrambler26.

Thereby, the descrambler 26 creates the original local scramble key dataD20 by decoding the encrypted scramble key data D21 given from the CPU 2with information unique to the recording/reproduction apparatus 1.

In addition, the descrambler 26 decodes the encrypted compressed andencoded video data and compressed and encoded audio data being stored inthe reproduction encrypted transport stream TS5 given from the hard diskdrive 5, with the local scramble key data D20, to create and send areproduction transport stream TS6 to the demultiplexer 15.

At this time, the demultiplexer 15 separates the section TS packet data,and the video TS packet data and audio TS packet data of the copyprotected program to be reproduced, from the reproduction transportstream TS6 given from the descrambler 26, under the control of the CPU 2based on the program information being stored in the reproductionprocedure information.

Then the demultiplexer 15 sends the video PES packet data D25 createdbased on the video TS packet data, the audio PES packet data D26 createdbased on the audio TS packet data, and the section data D18 createdbased on the section TS packet data, to the video decoder 16, the audiodecoder 17, and the memory 18.

Further, the CPU 2 reads the section data D18 from the memory 18, andcontrols the video decoder 16 and the audio decoder 17 based on an orderof decoding indicated by the additional information being stored in thesection data D18.

Thereby, the video decoder 16 and the audio decoder 17 execute the sameprocesses as the above-described case of watching a digital televisionprogram, so as to send the video signal S15 based on the video PESpacket data D25 to the external video display unit 20 and also send theaudio signal S16 based on the audio PES packet data D26 to the externalaudio output unit 21.

As described above, the CPU 2 can allow the user to watch a copyprotected program temporarily stored, within a reproducible rangeallowed to be watched, according to a temporary storage allowable time,via the video display unit 20 and the audio output unit 21.

Further, at a time of reproducing a recorded copy permitted program, theCPU 2 reads the reproduction management information corresponding to thecopy permitted program from the hard disk drive 5 via the memory 25 andalso reads reproduction procedure information based on the reproductionmanagement information, based on the copy permitted program to bereproduced specified with the operating unit 9 and a reproductioncommand.

Then the CPU 2 controls the hard disk drive 5 via the memory 25 based onthe stream file name and stream management information being stored inthe reproduction procedure information, and the reproducible start pointinformation and reproducible end point information being stored in thestream reproduction management information, sends the encrypted scramblekey data D21 being stored in the reproduction management information tothe descrambler 26, and controls the demultiplexer 15 based on theprogram information being stored in the reproduction procedureinformation.

Thereby, the hard disk drive 5 reads a data part (that is, entireencrypted transport stream TS4) within a reproducible range between thereproducible start point and the reproducible end point specified by thetime stamps of the reproducible start point information and thereproducible end point information for the encrypted transport streamTS4 corresponding to the copy permitted program to be reproduced, fromthe hard disk, and sends this to the descrambler 26.

In addition, the descrambler 26 creates the original local scramble keydata D20 by decoding the encrypted scramble key data D21 given from theCPU 2 with information unique to the recording/reproducing apparatus 1,and creates the original recording transport stream TS3 by decoding theencrypted compressed and encoded video data and compressed and encodedaudio data being stored in the encrypted transport stream TS4 given fromthe hard disk drive 5, with the local scramble key data D20, and sendsthem to the demultiplexer-15.

At this time, the demultiplexer 15 separates the section TS packet data,and the video TS packet data and audio TS packet data of the copyprotected program to be reproduced, from the recording transport streamTS3 given from the descrambler 26, under the control of the CPU 2according to the program information being stored in the reproductionprocedure information.

Then the demultiplxer 15 sends the video PES packet data D16 createdbased on the video TS packet data, the audio PES packet data D17 createdbased on the audio TS packet data and the section data D18 created basedon the section TS packet data, to the video decoder 16, the audiodecoder 17 and the memory 18.

In addition, the CPU 2 reads the section data D18 from the memory 18 andcontrols the video decoder 16 and the audio decoder 17 based on an orderof decoding indicated by the additional information being stored in thesection data D18.

Thereby the video decoder 16 and the audio decoder 17 execute the sameprocesses as the above-described case of watching a digital televisionprogram, thereby sending the video signal S11 based on the video PESpacket data D16 to the external video display unit 20 and sending theaudio signal S12 based on the audio PES packet data D17 to the externalaudio output unit 21.

As described above, the CPU 2 can allow the user to watch the recordedcopy permitted program via the video display unit 20 and the audiooutput unit 21.

According to the above configuration, when recording of a copy protectedprogram is instructed while the copy protected program is watched, therecording/reproducing apparatus 1 creates the recording transport streamTS3 corresponding to the copy protected program to be recorded based onthe television signal S10 being received, and locally encrypts andrecords the created recording transport stream TS3 in the hard disk ofthe hard disk drive 5 for temporary storage (step SP1).

In addition, while extracting the time stamps from the GOP partsincluded in the recording transport stream TS3, therecording/reproducing apparatus 1 creates the reproducible start pointinformation by associating the first time stamp with a reproduciblestart point, and changes the time stamp which is associated with areproducible end point while associating a time stamp temporallyfollowing the first time stamp with the reproducible end point to updatethe contents of the reproducible end point information until therecording of the copy protected program is finished (step SP2 to stepSP4).

Then the recording/reproducing apparatus 1 determines at prescribedperiods whether the reproduction disabling detection time which is thetemporary storage allowable time before the current time matches thetemporary storage start time indicated by the time stamp associated withthe reproducible start time. When they almost match, the apparatus 1updates the contents of the reproducible start point information byre-associating a time stamp temporally following the time stampassociated with the reproducible start point with the reproducible startpoint (step SP5 to step SP7).

As a result, without using a special file system to sequentially deleteovertime parts of the recording transport stream TS3 to be recorded as afile as in the case of a data deletion method exemplified by theoperational guidelines for digital terrestrial television broadcasting,even if a copy protected program is temporarily stored, therecording/reproducing apparatus 1 can correctly remove an overtime partof the recording transport stream TS3 from the reproducible range fromthe reproducible start point to the reproducible end point so as todisable its reproduction.

In addition, as compared with the local scramble key deletion methodexemplified by the operational guidelines for digital terrestrialtelevision broadcasting, the recording/reproduction apparatus 1 canremove an overtime part of the recording transport stream TS3corresponding to a copy protected program from a reproducible range tocorrectly disable its reproduction, without executing complicatedprocesses including sequentially creating a local scramble key for eachmanagement time when the copy protected program is temporally stored andmanaging a large number of local scramble keys for the temporary storageallowable time.

In addition, along with updating the reproducible start pointinformation of a recording transport stream TS3 corresponding to a copyprotected program temporarily stored, the recording/reproducingapparatus 1 associates the same time stamp with a reproducible startpoint and a reproducible end point and then when the time stamp almostmatches the reproduction disabling detection time, deletes thereproducible start point information and the reproducible end pointinformation.

Therefore, the recording/reproducing apparatus 1 cannot detect thereproducible start point and the reproducible end point for therecording transport stream TS3 corresponding to the copy protectedprogram even when trying to reproduce the copy protected program overthe temporary storage allowable time, and thus cannot reproduce therecording transport stream TS3. Thus the apparatus 1 can entirely removethe recording transport stream TS3 of the copy protected program storedover the temporary storage allowable time at the time of reproduction,from the reproducible range to correctly disable its reproduction.

According to the above configuration, when the recording transportstream TS3 corresponding to a copy protected program which is allowed tobe temporarily stored only from a temporary storage start time to atemporary storage end time is temporarily stored in the hard disk, thefirst time stamp is associated with a reproducible start point whiletime stamps of the GOP parts are extracted from the recording transportstream TS3, and then every time a period from the temporary storageallowable time indicated by the first time stamp to the current timereaches the temporary storage allowable time, another time stamptemporally following the time stamp is re-associated with thereproducible start point. Therefore, every time when an overtime part iscreated in the recording transport stream TS3 corresponding to the copyprotected program temporarily stored, the overtime part is removed fromthe reproducible range between the reproducible start point and thereproducible end point to easily and correctly disable its reproduction,thus making it possible to realize a recording/reproducing apparatuscapable of easily and correctly managing the temporary storage of copyprotected programs according to guidelines.

In addition, along with updating reproducible start point information ofthe recording transport stream TS3 corresponding to a copy protectedprogram temporarily stored, the same time stamp is associated with areproducible start point and a reproducible end point and then when thetime stamp almost matches the reproduction disabling detection time, thereproducible start point information and the reproducible end pointinformation are deleted. Thereby, even the recording transport streamTS3 corresponding to the copy protected program is entirely stored overthe temporary storage allowable time, the recording transport stream ST3can be prevented from being reproduced erroneously, thus making itpossible to realize a recording/reproducing apparatus capable oftemporarily storing the copy protected program only within the temporarystorage allowable time correctly.

Further, while the recording transport stream TS3 corresponding to thecopy protected program is recorded in the hard disk for temporarystorage, reproducible start point information and reproducible end pointinformation required for reproduction of the recording transport streamTS3, and encrypted scramble key data D21 are stored in the volatilememory 4, and power supply to the volatile memory 4 is stopped when therecording/reproducing apparatus 1 is stopped. Therefore, even if therecording/reproducing apparatus 1 is stopped before the reproduction ofthe copy protected program is disabled due to a lapse of the temporarystorage allowable time, the reproducible start point information, thereproducible end point information, and the encrypted scramble key dataD21 in the volatile memory 4 are deleted according to the stop.Therefore, the recording transport stream TS3 stored over the temporarystorage allowable time cannot be reproduced even when therecording/reproducing apparatus 1 starts again, resulting in beingcapable of safely and surely protecting the copyright of the copyprotected program.

In addition, according to the above configuration, the reproduciblestart point information, the reproducible end point information and theencrypted scramble key data D21 are stored in the volatile memory 4, notin the hard disk used to record the recording transport stream TS3.Therefore, the frequency of access to the hard disk can be preventedfrom increasing due to updating the reproducible start point informationand the reproducible end point information and recording and reproducingthe encrypted scramble key data D21. In addition, in actual, the harddisk is accessed only when the recording transport stream TS3 isrecorded and reproduced, resulting in decreasing the frequency of accessto the hard disk. Thus even when a digital television program isrecorded/reproduced in/from the hard disk at a relatively high transferrate, processing loads in the hard disk drive 5 can be prevented fromincreasing.

Furthermore, when the recording transport stream TS3 corresponding to acopy protected program is temporarily recorded, a time stamp isassociated with a reproducible start point while time stamps areextracted from the GOP parts accompanying with sequence headers of therecording transport stream TS3, the time stamp shorter than a managementtime for temporary storage. And then every time when a period from thetemporary storage start time indicated by the time stamp to the currenttime reaches the temporary storage allowable time, a time stamptemporally following the time stamp associated with the reproduciblestart point is re-associated with the reproducible start point.Therefore, in addition to an effect in which the reproduction of thecopy protected program can be easily and correctly disabled, thereproducible start point is always associated with the time stamp whichis a randomly accessible point, thereby simplifying control thereproduction of the copy protected program.

Note that the above-described embodiment has described a case ofsequentially extracting time stamps each indicating a temporary storagestart time, from the GOP parts of the recording transport stream TS3corresponding to a copy protected program when the copy protectedprogram is temporarily stored. This invention, however, is not limitedto this and a temporary storage start time can be sequentiallyassociated with a prescribed part of the recording transport steam TS3on the recording/reproducing apparatus 1 side.

Then, when a temporary storage start time is sequentially associatedwith a prescribed part of the recording transport stream TS3 on therecording/reproducing apparatus 1 side, a reproducible start point canbe re-associated with a temporary storage start time which is adesirably selected prescribed time after the temporary storage starttime, every time when a period from the temporary storage start timeassociated with the reproducible start point to the current time reachesthe temporary storage allowable time, provided that the reproduction ofan overtime part can be disabled according to the guidelines fortemporary storage.

Further, the above embodiment has described a case of executing thetemporary storage management procedure RT1 described with reference toFIG. 7 with the temporary storage management program being stored in thehard disk of the recording/reproducing apparatus 1. This invention,however, is not limited to this and the temporary storage managementprocedure RT1 can be executed by installing the temporary storagemanagement program in the recording/reproducing apparatus 1 via wired-or wireless communication media such as a local area network, theInternet, and digital satellite broadcasting. Alternatively, thetemporary storage management procedure RT1 can be executed by installinga program storage medium storing the temporary storage managementprogram in the recording/reproducing apparatus 1.

In this connection, as a program storage medium for installing thetemporary storage management program to execute the temporary storagemanagement procedure RT1 in the recording/reproducing apparatus 1 toexecute the program, not only package media such as CD-ROM (CompactDisk-Read Only Memory) and DVD (Digital Versatile Disc) but alsosemiconductor memories or magnetic disks for temporarily or permanentlystoring the temporary storage management program can be used. Inaddition, as a means for storing the temporary storage managementprogram in a program storage medium, wired and wireless communicationmedia such as local area network, the Internet, and digital satellitebroadcasting can be used, and the program can be stored via variouscommunication interfaces such as routers and modems.

Furthermore, the above embodiment has described a case of applying thetemporary storage management apparatus according to this invention tothe recording/reproducing apparatus 1 which records and reproduces acopy protected program of digital terrestrial television broadcastingdescribed with reference to FIG. 1 to FIG. 7. This invention, however,is not limited to this and can be widely applied to temporary storagemanagement apparatuses of other kinds such as personal computers,portable telephones, and audio devices which record/reproduce contentdata comprising video data and content data comprising audio data whichare allowed to be temporarily stored for reproduction only within atemporary storage allowable time.

Furthermore, the above embodiment has described a case of applying therecording transport stream TS3 corresponding to a copy protected programof digital terrestrial television broadcasting described with referenceto FIG. 1 to FIG. 7, as content data which is allowed to be temporarilystored in a recording medium for reproduction only within a prescribedtemporary storage allowable time. This invention, however, is notlimited to this and other kinds of content data can be widely applied,such as content data comprising video data and content data comprisingaudio data of a broadcasting program on for example, a network such asthe Internet, cable television broadcasting, analog terrestrialtelevision broadcasting, and satellite digital television broadcastingand radio broadcasting, content data comprising video and/or audio datato be broadcast without being compressed and encoded, and content datacomprising video and/or audio data corresponding one or a plurality ofprescribed parts excepting commercials in one program.

Furthermore, the above embodiment has described a case of applying thehard disk of the hard disk drive 5 described above with reference toFIG. 1 to FIG. 7, as a recording medium for temporarily storing contentdata which is allowed to be temporarily stored so as to be reproducibleonly within a prescribed temporary storage allowable time. Thisinvention, however, is not limited to this and other recording media canbe widely applied, such as semiconductor memories and magnetic opticaldiscs.

Furthermore, the above embodiment has described a case of applying theCPU 2 described above with reference to FIG. 1 to FIG. 7 as anassociation means for associating the first temporary storage start timeout of the temporary storage start times of prescribed parts of contentdata, with a reproducible start point indicating a start point fromwhich the content data can be reproduced. This invention, however, isnot limited to this and other association means can be widely applied,such as a microprocessor.

Furthermore, the above embodiment has described a case of applying theCPU 2 described above with reference to FIG. 1 to FIG. 7 as anassociation changing means for re-associating a temporary storage starttime temporally following the temporary storage start time with thereproducible start point every time when a period from a temporarystorage start time associated with the reproducible start point to thecurrent time reaches the temporary storage allowable time. Thisinvention, however, is not limited to this and other associationchanging means can be widely applied, such as a microprocessor.

Furthermore, the above embodiment has described a case of applying thevolatile memory 4 described above with reference to FIG. 1 to FIG. 7, asan information recording means for recording history information oftemporary storage of content data and recording of copy allowed contentdata in a recording medium when the copy allowed content data allowingcopy without restriction or copy one generation is recorded togetherwith content data which is allowed to be temporarily stored. Thisinvention, however, is not limited to this and other informationrecording means can be widely applied, such as the hard disk of therecording/reproducing apparatus 1.

Furthermore, the above embodiment has described a case of applying theCPU 2 described above with reference to FIG. 1 to FIG. 7 as adetermination means for determining based on history information whethercontent data was temporarily stored at the reproduction disablingdetection time when the reproduction disabling detection time which is atemporary storage allowable time before the current time, almost matchesthe temporary storage start time associated with the reproducible startpoint. This invention, however, is not limited to this and otherdetermination means can be widely applied, such as a microprocessor.

Furthermore, the above embodiment has described a case of applying theinformation extraction circuit 33 described above with reference to FIG.1 to FIG. 7 as a start time extraction means for sequentially extractingtemporary storage start times added to intra frame encoded images, fromthe content data comprising video data created by sequentiallycompressing and encoding prescribed parts each including a plurality offrame images in which the beginning is an inter frame encoded image.This invention, however, is not limited to this and other start timeextraction means can be widely applied, such as a CPU which extracts atemporary storage start time of a prescribed part different from a GOP,from the content data.

As described above, according to this invention, when temporary storageof content data which is allowed to be temporarily stored in a recordingmedium so as to be reproducible only within a prescribed temporarystorage allowable time, a reproducible start point indicating a startpoint from which the content data can be reproduced is associated withthe first temporary storage start time out of the temporary storagestart times of prescribed parts of the content data, and every time whena period from the temporary storage start time associated with thereproducible start point to the current time reaches the temporarystorage allowable time, a temporary storage start time following thetemporary storage start time is re-associated with the reproduciblestart point. Therefore, an overtime part of the temporarily storedcontent data is removed from a reproducible range which is a temporarystorage range within the temporary storage allowable time by beingsequentially located before the reproducible start point, so as todisable its reproduction easily and correctly, thus making it possibleto realize a temporary storage management apparatus capable of easilyand correctly managing the temporary storage of content data accordingto guidelines.

INDUSTRIAL APPLICABILITY

This invention can be used for temporary storage management apparatusessuch as hard disk recorders, personal computers, and portabletelephones.

1. A temporary storage management apparatus for managing temporarystorage of content data allowed to be temporarily stored in a recordingmedium so as to be reproducible only within a prescribed temporarystorage allowable time, said temporary storage management apparatuscomprising: association means for associating a first temporary storagestart time out of temporary storage start times of prescribed parts ofthe content data with a reproducible start point indicating a startpoint from which the content data can be reproduced; and associationchanging means for re-associating another temporary storage start timefollowing the temporary storage start time with the reproducible startpoint every time when a period from the temporary storage start timeassociated with the reproducible start point to a current time reachesthe temporary storage allowable time.
 2. The temporary storagemanagement apparatus according to claim 1, further comprising a volatilememory for storing information of the temporary storage start timeassociated with the reproducible start time.
 3. The temporary storagemanagement apparatus according to claim 2, wherein said volatile memorystores encrypted key data used for encryption of the content datatemporarily stored in said recording medium after being encrypted. 4.The temporary storage management apparatus according to claim 1, furthercomprising: information recording means for, when copy allowed contentdata allowing copy without restrictions or copy one generation isrecorded with the content data which is allowed to be temporarilystored, recording history information of temporary storage of thecontent data and recording of the copy allowed content data in saidrecording medium; and determination means for, when a reproductiondisabling detection time which is the temporary storage allowable timebefore the current time almost matches the temporary storage start timeassociated with the reproducible start point, determining based on thehistory information whether the content data was temporarily stored atthe reproduction disabling detection time, wherein said reproduciblerange updating means changes the temporary storage start time to beassociated with the reproducible start point, depending on adetermination result of the determination means, only when the contentdata was temporarily stored at the reproduction disabling detectiontime.
 5. The temporary storage management apparatus according to claim1, further comprising start time extraction means for sequentiallyextracting the temporary storage start time added to an inter frameencoded image, from the content data comprising video data created bysequentially compressing and encoding the prescribed parts each having aplurality of frame images with a beginning as the inter frame encodedimage.
 6. A temporary storage management method for managing temporarystorage of content data allowed to be temporarily stored in a recordingmedium so as to be reproducible only within a prescribed temporarystorage allowable time, said temporary storage management methodcomprising: an association step of associating a first temporary storagestart time out of temporary storage start times of prescribed parts ofthe content data with a reproducible start point indicating a startpoint from which the content data can be reproduced; and an associationchanging step of re-associating another temporary storage start timefollowing the temporary storage start time with the reproducible startpoint every time when a period from the temporary storage start timeassociated with the reproducible start point to a current time reachesthe temporary storage allowable time.
 7. A temporary management programcausing a computer to execute: an association step of associating afirst temporary storage start time out of temporary storage start timesof prescribed parts of content data which is allowed to be temporarilystored in a recording medium so as to be reproducible only within aprescribed temporary storage allowable time, with a reproducible startpoint indicating a start point from which the content data can bereproduced; and an association changing step of re-associating anothertemporary storage start time following the temporary storage start timewith the reproducible start point every time when a period from thetemporary storage start time associated with the reproducible startpoint to a current time reaches the temporary storage allowable time.